A Detroit police K-9 officer has been assigned to patrol duty as he awaits word on possible discipline after his police dog died after being left in a hot vehicle.

The incident happened June 26. Detroit Police Cmdr. Darin Szilagy said the officer started his vehicle with a remote start and left his German shepherd Vito inside with the air conditioner running while he and another officer left to pick up a different vehicle.

When the officer returned after about 40 minutes, Szilagy said, he found the vehicle off and Vito suffering from obvious signs of heat stroke. The dog was rushed to an emergency veterinarian. He died from cardiac arrest the next day.

The department launched an internal probe.

"The investigation found while there were mechanical issues with the vehicle, the officer was also found responsible for the incident," Szilagy said. "Our policy is that you should check the dog every 30 minutes, no matter what."

Szilagy said the vehicle's heat alarm system failed. He also said the investigation revealed that the officer knew that the vehicle would sometimes shut off, but never reported it so it could be fixed.

"So if something would happen to the vehicle and it shuts off and the temperature reaches 95 degrees inside, the vehicle is supposed to lower the windows, turn on some fans, and start honking to alert someone the vehicle is off. ... At some point while they were gone, the police vehicle had turned off, and the heat alarm system failed," Szilagy said.

The high temperature on June 26 in Detroit was 78 degrees, according to the National Weather Service. It was sunny all day.

Vehicles can quickly overheat in warm weather. According to the American Society for the Prevention of Cruelty to Animals, on an 85-degree day, it takes just 30 minutes for an interior of a car to reach 120 degrees.

Szilagy said the internal investigation is complete. The officer has been assigned patrol duties while he awaits news of possible discipline from the department's disciplinary administration unit.

Szilagy said the officer doesn't have any disciplinary history and is broken up over what happened.

"The officer is distraught over the incident. He is a very good officer," Szilagy said. "He was training rigorously with that dog. He is beyond consolation."